This invention relates to emergency fountain wash receptacles, and in particular, to a portable, self-contained, emergency eye wash station.
There is an ongoing need to protect the health and safety of workers. For this reason, it is common to find eye wash fountains at industrial work stations, laboratories, and other locations where workers are exposed to gaseous fumes, liquids or solid materials which can irritate or injure a worker's eyes. The Occupational Safety and Health Administration (OSHA) has made eye wash fountains mandatory for particular industrial work stations.
Some prior art devices have employed eye wash fountains providing sprays of water from regular plant plumbing connections. Other prior art devices are self-contained, gravity-fed, and independent of any plumbing connections. Such eye wash fountains typically contain a reservoir of wash fluid spaced above two opposed liquid spray nozzles. Upon activating the fluid flow, the wash fluid from the reservoir is fed solely by gravity to the nozzles to cause a gravity-induced spray of wash fluid from the nozzles.
The American National Standards Institute (ANSI) has promulgated standards for portable eye wash fountains relating to flushing periods and the rate of flow of wash fluid. These standards dictate that portable eye wash fountains should deliver no less than 0.4 gallons per minute of eye wash fluid in a 6 inch spray for a time period of 15 minutes.
Prior art portable eye wash stations typically contain a tank of fluid which is elevated with respect to flow outlet configured to spray a fluid stream into the user's eyes. A station tank must be refilled after a station has been used or every six months as a periodic maintenance, whichever is sooner. Because of the difficulties in refilling a tank without spillage or without introducing contaminants, prior art wash stations use bags of liquids to refill the tank.
A drawback of the gravity-fed eye wash fountains of the type described above is that they contain fluid significantly in excess of the amount required for actual flushing to meet ANSI standards. The reason for this is that the rate of flow of wash fluid from the gravity-fed eye wash fountains of the prior art decreases over time. The fluid pressure at an eye wash spray nozzle is a function of fluid head at the inlet to the nozzle. As fluid is used and the tank is gradually emptied, the fluid height within the tank, the consequent hydraulic head at the spray nozzle inlet, and thereby both liquid flow rate through the spray nozzle and height of a spray pattern from the spray nozzle gradually diminish. therefore, in order to ensure meeting ANSI standards, prior art tanks contain 16 gallons of fluid.